JDK8/Java8源码在线阅读
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
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* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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*/
package java.awt.geom;
import java.awt.Shape;
import java.awt.Rectangle;
import java.io.Serializable;
/**
* This <code>Line2D</code> represents a line segment in {@code (x,y)}
* coordinate space. This class, like all of the Java 2D API, uses a
* default coordinate system called <i>user space</i> in which the y-axis
* values increase downward and x-axis values increase to the right. For
* more information on the user space coordinate system, see the
* <a href="https://docs.oracle.com/javase/1.3/docs/guide/2d/spec/j2d-intro.fm2.html#61857">
* Coordinate Systems</a> section of the Java 2D Programmer's Guide.
* <p>
* This class is only the abstract superclass for all objects that
* store a 2D line segment.
* The actual storage representation of the coordinates is left to
* the subclass.
*
* @author Jim Graham
* @since 1.2
*/
public abstract class Line2D implements Shape, Cloneable {
/**
* A line segment specified with float coordinates.
* @since 1.2
*/
public static class Float extends Line2D implements Serializable {
/**
* The X coordinate of the start point of the line segment.
* @since 1.2
* @serial
*/
public float x1;
/**
* The Y coordinate of the start point of the line segment.
* @since 1.2
* @serial
*/
public float y1;
/**
* The X coordinate of the end point of the line segment.
* @since 1.2
* @serial
*/
public float x2;
/**
* The Y coordinate of the end point of the line segment.
* @since 1.2
* @serial
*/
public float y2;
/**
* Constructs and initializes a Line with coordinates (0, 0) → (0, 0).
* @since 1.2
*/
public Float() {
}
/**
* Constructs and initializes a Line from the specified coordinates.
* @param x1 the X coordinate of the start point
* @param y1 the Y coordinate of the start point
* @param x2 the X coordinate of the end point
* @param y2 the Y coordinate of the end point
* @since 1.2
*/
public Float(float x1, float y1, float x2, float y2) {
setLine(x1, y1, x2, y2);
}
/**
* Constructs and initializes a <code>Line2D</code> from the
* specified <code>Point2D</code> objects.
* @param p1 the start <code>Point2D</code> of this line segment
* @param p2 the end <code>Point2D</code> of this line segment
* @since 1.2
*/
public Float(Point2D p1, Point2D p2) {
setLine(p1, p2);
}
/**
* {@inheritDoc}
* @since 1.2
*/
public double getX1() {
return (double) x1;
}
/**
* {@inheritDoc}
* @since 1.2
*/
public double getY1() {
return (double) y1;
}
/**
* {@inheritDoc}
* @since 1.2
*/
public Point2D getP1() {
return new Point2D.Float(x1, y1);
}
/**
* {@inheritDoc}
* @since 1.2
*/
public double getX2() {
return (double) x2;
}
/**
* {@inheritDoc}
* @since 1.2
*/
public double getY2() {
return (double) y2;
}
/**
* {@inheritDoc}
* @since 1.2
*/
public Point2D getP2() {
return new Point2D.Float(x2, y2);
}
/**
* {@inheritDoc}
* @since 1.2
*/
public void setLine(double x1, double y1, double x2, double y2) {
this.x1 = (float) x1;
this.y1 = (float) y1;
this.x2 = (float) x2;
this.y2 = (float) y2;
}
/**
* Sets the location of the end points of this <code>Line2D</code>
* to the specified float coordinates.
* @param x1 the X coordinate of the start point
* @param y1 the Y coordinate of the start point
* @param x2 the X coordinate of the end point
* @param y2 the Y coordinate of the end point
* @since 1.2
*/
public void setLine(float x1, float y1, float x2, float y2) {
this.x1 = x1;
this.y1 = y1;
this.x2 = x2;
this.y2 = y2;
}
/**
* {@inheritDoc}
* @since 1.2
*/
public Rectangle2D getBounds2D() {
float x, y, w, h;
if (x1 < x2) {
x = x1;
w = x2 - x1;
} else {
x = x2;
w = x1 - x2;
}
if (y1 < y2) {
y = y1;
h = y2 - y1;
} else {
y = y2;
h = y1 - y2;
}
return new Rectangle2D.Float(x, y, w, h);
}
/*
* JDK 1.6 serialVersionUID
*/
private static final long serialVersionUID = 6161772511649436349L;
}
/**
* A line segment specified with double coordinates.
* @since 1.2
*/
public static class Double extends Line2D implements Serializable {
/**
* The X coordinate of the start point of the line segment.
* @since 1.2
* @serial
*/
public double x1;
/**
* The Y coordinate of the start point of the line segment.
* @since 1.2
* @serial
*/
public double y1;
/**
* The X coordinate of the end point of the line segment.
* @since 1.2
* @serial
*/
public double x2;
/**
* The Y coordinate of the end point of the line segment.
* @since 1.2
* @serial
*/
public double y2;
/**
* Constructs and initializes a Line with coordinates (0, 0) → (0, 0).
* @since 1.2
*/
public Double() {
}
/**
* Constructs and initializes a <code>Line2D</code> from the
* specified coordinates.
* @param x1 the X coordinate of the start point
* @param y1 the Y coordinate of the start point
* @param x2 the X coordinate of the end point
* @param y2 the Y coordinate of the end point
* @since 1.2
*/
public Double(double x1, double y1, double x2, double y2) {
setLine(x1, y1, x2, y2);
}
/**
* Constructs and initializes a <code>Line2D</code> from the
* specified <code>Point2D</code> objects.
* @param p1 the start <code>Point2D</code> of this line segment
* @param p2 the end <code>Point2D</code> of this line segment
* @since 1.2
*/
public Double(Point2D p1, Point2D p2) {
setLine(p1, p2);
}
/**
* {@inheritDoc}
* @since 1.2
*/
public double getX1() {
return x1;
}
/**
* {@inheritDoc}
* @since 1.2
*/
public double getY1() {
return y1;
}
/**
* {@inheritDoc}
* @since 1.2
*/
public Point2D getP1() {
return new Point2D.Double(x1, y1);
}
/**
* {@inheritDoc}
* @since 1.2
*/
public double getX2() {
return x2;
}
/**
* {@inheritDoc}
* @since 1.2
*/
public double getY2() {
return y2;
}
/**
* {@inheritDoc}
* @since 1.2
*/
public Point2D getP2() {
return new Point2D.Double(x2, y2);
}
/**
* {@inheritDoc}
* @since 1.2
*/
public void setLine(double x1, double y1, double x2, double y2) {
this.x1 = x1;
this.y1 = y1;
this.x2 = x2;
this.y2 = y2;
}
/**
* {@inheritDoc}
* @since 1.2
*/
public Rectangle2D getBounds2D() {
double x, y, w, h;
if (x1 < x2) {
x = x1;
w = x2 - x1;
} else {
x = x2;
w = x1 - x2;
}
if (y1 < y2) {
y = y1;
h = y2 - y1;
} else {
y = y2;
h = y1 - y2;
}
return new Rectangle2D.Double(x, y, w, h);
}
/*
* JDK 1.6 serialVersionUID
*/
private static final long serialVersionUID = 7979627399746467499L;
}
/**
* This is an abstract class that cannot be instantiated directly.
* Type-specific implementation subclasses are available for
* instantiation and provide a number of formats for storing
* the information necessary to satisfy the various accessory
* methods below.
*
* @see java.awt.geom.Line2D.Float
* @see java.awt.geom.Line2D.Double
* @since 1.2
*/
protected Line2D() {
}
/**
* Returns the X coordinate of the start point in double precision.
* @return the X coordinate of the start point of this
* {@code Line2D} object.
* @since 1.2
*/
public abstract double getX1();
/**
* Returns the Y coordinate of the start point in double precision.
* @return the Y coordinate of the start point of this
* {@code Line2D} object.
* @since 1.2
*/
public abstract double getY1();
/**
* Returns the start <code>Point2D</code> of this <code>Line2D</code>.
* @return the start <code>Point2D</code> of this <code>Line2D</code>.
* @since 1.2
*/
public abstract Point2D getP1();
/**
* Returns the X coordinate of the end point in double precision.
* @return the X coordinate of the end point of this
* {@code Line2D} object.
* @since 1.2
*/
public abstract double getX2();
/**
* Returns the Y coordinate of the end point in double precision.
* @return the Y coordinate of the end point of this
* {@code Line2D} object.
* @since 1.2
*/
public abstract double getY2();
/**
* Returns the end <code>Point2D</code> of this <code>Line2D</code>.
* @return the end <code>Point2D</code> of this <code>Line2D</code>.
* @since 1.2
*/
public abstract Point2D getP2();
/**
* Sets the location of the end points of this <code>Line2D</code> to
* the specified double coordinates.
* @param x1 the X coordinate of the start point
* @param y1 the Y coordinate of the start point
* @param x2 the X coordinate of the end point
* @param y2 the Y coordinate of the end point
* @since 1.2
*/
public abstract void setLine(double x1, double y1, double x2, double y2);
/**
* Sets the location of the end points of this <code>Line2D</code> to
* the specified <code>Point2D</code> coordinates.
* @param p1 the start <code>Point2D</code> of the line segment
* @param p2 the end <code>Point2D</code> of the line segment
* @since 1.2
*/
public void setLine(Point2D p1, Point2D p2) {
setLine(p1.getX(), p1.getY(), p2.getX(), p2.getY());
}
/**
* Sets the location of the end points of this <code>Line2D</code> to
* the same as those end points of the specified <code>Line2D</code>.
* @param l the specified <code>Line2D</code>
* @since 1.2
*/
public void setLine(Line2D l) {
setLine(l.getX1(), l.getY1(), l.getX2(), l.getY2());
}
/**
* Returns an indicator of where the specified point
* {@code (px,py)} lies with respect to the line segment from
* {@code (x1,y1)} to {@code (x2,y2)}.
* The return value can be either 1, -1, or 0 and indicates
* in which direction the specified line must pivot around its
* first end point, {@code (x1,y1)}, in order to point at the
* specified point {@code (px,py)}.
* <p>A return value of 1 indicates that the line segment must
* turn in the direction that takes the positive X axis towards
* the negative Y axis. In the default coordinate system used by
* Java 2D, this direction is counterclockwise.
* <p>A return value of -1 indicates that the line segment must
* turn in the direction that takes the positive X axis towards
* the positive Y axis. In the default coordinate system, this
* direction is clockwise.
* <p>A return value of 0 indicates that the point lies
* exactly on the line segment. Note that an indicator value
* of 0 is rare and not useful for determining collinearity
* because of floating point rounding issues.
* <p>If the point is colinear with the line segment, but
* not between the end points, then the value will be -1 if the point
* lies "beyond {@code (x1,y1)}" or 1 if the point lies
* "beyond {@code (x2,y2)}".
*
* @param x1 the X coordinate of the start point of the
* specified line segment
* @param y1 the Y coordinate of the start point of the
* specified line segment
* @param x2 the X coordinate of the end point of the
* specified line segment
* @param y2 the Y coordinate of the end point of the
* specified line segment
* @param px the X coordinate of the specified point to be
* compared with the specified line segment
* @param py the Y coordinate of the specified point to be
* compared with the specified line segment
* @return an integer that indicates the position of the third specified
* coordinates with respect to the line segment formed
* by the first two specified coordinates.
* @since 1.2
*/
public static int relativeCCW(double x1, double y1,
double x2, double y2,
double px, double py)
{
x2 -= x1;
y2 -= y1;
px -= x1;
py -= y1;
double ccw = px * y2 - py * x2;
if (ccw == 0.0) {
// The point is colinear, classify based on which side of
// the segment the point falls on. We can calculate a
// relative value using the projection of px,py onto the
// segment - a negative value indicates the point projects
// outside of the segment in the direction of the particular
// endpoint used as the origin for the projection.
ccw = px * x2 + py * y2;
if (ccw > 0.0) {
// Reverse the projection to be relative to the original x2,y2
// x2 and y2 are simply negated.
// px and py need to have (x2 - x1) or (y2 - y1) subtracted
// from them (based on the original values)
// Since we really want to get a positive answer when the
// point is "beyond (x2,y2)", then we want to calculate
// the inverse anyway - thus we leave x2 & y2 negated.
px -= x2;
py -= y2;
ccw = px * x2 + py * y2;
if (ccw < 0.0) {
ccw = 0.0;
}
}
}
return (ccw < 0.0) ? -1 : ((ccw > 0.0) ? 1 : 0);
}
/**
* Returns an indicator of where the specified point
* {@code (px,py)} lies with respect to this line segment.
* See the method comments of
* {@link #relativeCCW(double, double, double, double, double, double)}
* to interpret the return value.
* @param px the X coordinate of the specified point
* to be compared with this <code>Line2D</code>
* @param py the Y coordinate of the specified point
* to be compared with this <code>Line2D</code>
* @return an integer that indicates the position of the specified
* coordinates with respect to this <code>Line2D</code>
* @see #relativeCCW(double, double, double, double, double, double)
* @since 1.2
*/
public int relativeCCW(double px, double py) {
return relativeCCW(getX1(), getY1(), getX2(), getY2(), px, py);
}
/**
* Returns an indicator of where the specified <code>Point2D</code>
* lies with respect to this line segment.
* See the method comments of
* {@link #relativeCCW(double, double, double, double, double, double)}
* to interpret the return value.
* @param p the specified <code>Point2D</code> to be compared
* with this <code>Line2D</code>
* @return an integer that indicates the position of the specified
* <code>Point2D</code> with respect to this <code>Line2D</code>
* @see #relativeCCW(double, double, double, double, double, double)
* @since 1.2
*/
public int relativeCCW(Point2D p) {
return relativeCCW(getX1(), getY1(), getX2(), getY2(),
p.getX(), p.getY());
}
/**
* Tests if the line segment from {@code (x1,y1)} to
* {@code (x2,y2)} intersects the line segment from {@code (x3,y3)}
* to {@code (x4,y4)}.
*
* @param x1 the X coordinate of the start point of the first
* specified line segment
* @param y1 the Y coordinate of the start point of the first
* specified line segment
* @param x2 the X coordinate of the end point of the first
* specified line segment
* @param y2 the Y coordinate of the end point of the first
* specified line segment
* @param x3 the X coordinate of the start point of the second
* specified line segment
* @param y3 the Y coordinate of the start point of the second
* specified line segment
* @param x4 the X coordinate of the end point of the second
* specified line segment
* @param y4 the Y coordinate of the end point of the second
* specified line segment
* @return <code>true</code> if the first specified line segment
* and the second specified line segment intersect
* each other; <code>false</code> otherwise.
* @since 1.2
*/
public static boolean linesIntersect(double x1, double y1,
double x2, double y2,
double x3, double y3,
double x4, double y4)
{
return ((relativeCCW(x1, y1, x2, y2, x3, y3) *
relativeCCW(x1, y1, x2, y2, x4, y4) <= 0)
&& (relativeCCW(x3, y3, x4, y4, x1, y1) *
relativeCCW(x3, y3, x4, y4, x2, y2) <= 0));
}
/**
* Tests if the line segment from {@code (x1,y1)} to
* {@code (x2,y2)} intersects this line segment.
*
* @param x1 the X coordinate of the start point of the
* specified line segment
* @param y1 the Y coordinate of the start point of the
* specified line segment
* @param x2 the X coordinate of the end point of the
* specified line segment
* @param y2 the Y coordinate of the end point of the
* specified line segment
* @return {@code <true>} if this line segment and the specified line segment
* intersect each other; <code>false</code> otherwise.
* @since 1.2
*/
public boolean intersectsLine(double x1, double y1, double x2, double y2) {
return linesIntersect(x1, y1, x2, y2,
getX1(), getY1(), getX2(), getY2());
}
/**
* Tests if the specified line segment intersects this line segment.
* @param l the specified <code>Line2D</code>
* @return <code>true</code> if this line segment and the specified line
* segment intersect each other;
* <code>false</code> otherwise.
* @since 1.2
*/
public boolean intersectsLine(Line2D l) {
return linesIntersect(l.getX1(), l.getY1(), l.getX2(), l.getY2(),
getX1(), getY1(), getX2(), getY2());
}
/**
* Returns the square of the distance from a point to a line segment.
* The distance measured is the distance between the specified
* point and the closest point between the specified end points.
* If the specified point intersects the line segment in between the
* end points, this method returns 0.0.
*
* @param x1 the X coordinate of the start point of the
* specified line segment
* @param y1 the Y coordinate of the start point of the
* specified line segment
* @param x2 the X coordinate of the end point of the
* specified line segment
* @param y2 the Y coordinate of the end point of the
* specified line segment
* @param px the X coordinate of the specified point being
* measured against the specified line segment
* @param py the Y coordinate of the specified point being
* measured against the specified line segment
* @return a double value that is the square of the distance from the
* specified point to the specified line segment.
* @see #ptLineDistSq(double, double, double, double, double, double)
* @since 1.2
*/
public static double ptSegDistSq(double x1, double y1,
double x2, double y2,
double px, double py)
{
// Adjust vectors relative to x1,y1
// x2,y2 becomes relative vector from x1,y1 to end of segment
x2 -= x1;
y2 -= y1;
// px,py becomes relative vector from x1,y1 to test point
px -= x1;
py -= y1;
double dotprod = px * x2 + py * y2;
double projlenSq;
if (dotprod <= 0.0) {
// px,py is on the side of x1,y1 away from x2,y2
// distance to segment is length of px,py vector
// "length of its (clipped) projection" is now 0.0
projlenSq = 0.0;
} else {
// switch to backwards vectors relative to x2,y2
// x2,y2 are already the negative of x1,y1=>x2,y2
// to get px,py to be the negative of px,py=>x2,y2
// the dot product of two negated vectors is the same
// as the dot product of the two normal vectors
px = x2 - px;
py = y2 - py;
dotprod = px * x2 + py * y2;
if (dotprod <= 0.0) {
// px,py is on the side of x2,y2 away from x1,y1
// distance to segment is length of (backwards) px,py vector
// "length of its (clipped) projection" is now 0.0
projlenSq = 0.0;
} else {
// px,py is between x1,y1 and x2,y2
// dotprod is the length of the px,py vector
// projected on the x2,y2=>x1,y1 vector times the
// length of the x2,y2=>x1,y1 vector
projlenSq = dotprod * dotprod / (x2 * x2 + y2 * y2);
}
}
// Distance to line is now the length of the relative point
// vector minus the length of its projection onto the line
// (which is zero if the projection falls outside the range
// of the line segment).
double lenSq = px * px + py * py - projlenSq;
if (lenSq < 0) {
lenSq = 0;
}
return lenSq;
}
/**
* Returns the distance from a point to a line segment.
* The distance measured is the distance between the specified
* point and the closest point between the specified end points.
* If the specified point intersects the line segment in between the
* end points, this method returns 0.0.
*
* @param x1 the X coordinate of the start point of the
* specified line segment
* @param y1 the Y coordinate of the start point of the
* specified line segment
* @param x2 the X coordinate of the end point of the
* specified line segment
* @param y2 the Y coordinate of the end point of the
* specified line segment
* @param px the X coordinate of the specified point being
* measured against the specified line segment
* @param py the Y coordinate of the specified point being
* measured against the specified line segment
* @return a double value that is the distance from the specified point
* to the specified line segment.
* @see #ptLineDist(double, double, double, double, double, double)
* @since 1.2
*/
public static double ptSegDist(double x1, double y1,
double x2, double y2,
double px, double py)
{
return Math.sqrt(ptSegDistSq(x1, y1, x2, y2, px, py));
}
/**
* Returns the square of the distance from a point to this line segment.
* The distance measured is the distance between the specified
* point and the closest point between the current line's end points.
* If the specified point intersects the line segment in between the
* end points, this method returns 0.0.
*
* @param px the X coordinate of the specified point being
* measured against this line segment
* @param py the Y coordinate of the specified point being
* measured against this line segment
* @return a double value that is the square of the distance from the
* specified point to the current line segment.
* @see #ptLineDistSq(double, double)
* @since 1.2
*/
public double ptSegDistSq(double px, double py) {
return ptSegDistSq(getX1(), getY1(), getX2(), getY2(), px, py);
}
/**
* Returns the square of the distance from a <code>Point2D</code> to
* this line segment.
* The distance measured is the distance between the specified
* point and the closest point between the current line's end points.
* If the specified point intersects the line segment in between the
* end points, this method returns 0.0.
* @param pt the specified <code>Point2D</code> being measured against
* this line segment.
* @return a double value that is the square of the distance from the
* specified <code>Point2D</code> to the current
* line segment.
* @see #ptLineDistSq(Point2D)
* @since 1.2
*/
public double ptSegDistSq(Point2D pt) {
return ptSegDistSq(getX1(), getY1(), getX2(), getY2(),
pt.getX(), pt.getY());
}
/**
* Returns the distance from a point to this line segment.
* The distance measured is the distance between the specified
* point and the closest point between the current line's end points.
* If the specified point intersects the line segment in between the
* end points, this method returns 0.0.
*
* @param px the X coordinate of the specified point being
* measured against this line segment
* @param py the Y coordinate of the specified point being
* measured against this line segment
* @return a double value that is the distance from the specified
* point to the current line segment.
* @see #ptLineDist(double, double)
* @since 1.2
*/
public double ptSegDist(double px, double py) {
return ptSegDist(getX1(), getY1(), getX2(), getY2(), px, py);
}
/**
* Returns the distance from a <code>Point2D</code> to this line
* segment.
* The distance measured is the distance between the specified
* point and the closest point between the current line's end points.
* If the specified point intersects the line segment in between the
* end points, this method returns 0.0.
* @param pt the specified <code>Point2D</code> being measured
* against this line segment
* @return a double value that is the distance from the specified
* <code>Point2D</code> to the current line
* segment.
* @see #ptLineDist(Point2D)
* @since 1.2
*/
public double ptSegDist(Point2D pt) {
return ptSegDist(getX1(), getY1(), getX2(), getY2(),
pt.getX(), pt.getY());
}
/**
* Returns the square of the distance from a point to a line.
* The distance measured is the distance between the specified
* point and the closest point on the infinitely-extended line
* defined by the specified coordinates. If the specified point
* intersects the line, this method returns 0.0.
*
* @param x1 the X coordinate of the start point of the specified line
* @param y1 the Y coordinate of the start point of the specified line
* @param x2 the X coordinate of the end point of the specified line
* @param y2 the Y coordinate of the end point of the specified line
* @param px the X coordinate of the specified point being
* measured against the specified line
* @param py the Y coordinate of the specified point being
* measured against the specified line
* @return a double value that is the square of the distance from the
* specified point to the specified line.
* @see #ptSegDistSq(double, double, double, double, double, double)
* @since 1.2
*/
public static double ptLineDistSq(double x1, double y1,
double x2, double y2,
double px, double py)
{
// Adjust vectors relative to x1,y1
// x2,y2 becomes relative vector from x1,y1 to end of segment
x2 -= x1;
y2 -= y1;
// px,py becomes relative vector from x1,y1 to test point
px -= x1;
py -= y1;
double dotprod = px * x2 + py * y2;
// dotprod is the length of the px,py vector
// projected on the x1,y1=>x2,y2 vector times the
// length of the x1,y1=>x2,y2 vector
double projlenSq = dotprod * dotprod / (x2 * x2 + y2 * y2);
// Distance to line is now the length of the relative point
// vector minus the length of its projection onto the line
double lenSq = px * px + py * py - projlenSq;
if (lenSq < 0) {
lenSq = 0;
}
return lenSq;
}
/**
* Returns the distance from a point to a line.
* The distance measured is the distance between the specified
* point and the closest point on the infinitely-extended line
* defined by the specified coordinates. If the specified point
* intersects the line, this method returns 0.0.
*
* @param x1 the X coordinate of the start point of the specified line
* @param y1 the Y coordinate of the start point of the specified line
* @param x2 the X coordinate of the end point of the specified line
* @param y2 the Y coordinate of the end point of the specified line
* @param px the X coordinate of the specified point being
* measured against the specified line
* @param py the Y coordinate of the specified point being
* measured against the specified line
* @return a double value that is the distance from the specified
* point to the specified line.
* @see #ptSegDist(double, double, double, double, double, double)
* @since 1.2
*/
public static double ptLineDist(double x1, double y1,
double x2, double y2,
double px, double py)
{
return Math.sqrt(ptLineDistSq(x1, y1, x2, y2, px, py));
}
/**
* Returns the square of the distance from a point to this line.
* The distance measured is the distance between the specified
* point and the closest point on the infinitely-extended line
* defined by this <code>Line2D</code>. If the specified point
* intersects the line, this method returns 0.0.
*
* @param px the X coordinate of the specified point being
* measured against this line
* @param py the Y coordinate of the specified point being
* measured against this line
* @return a double value that is the square of the distance from a
* specified point to the current line.
* @see #ptSegDistSq(double, double)
* @since 1.2
*/
public double ptLineDistSq(double px, double py) {
return ptLineDistSq(getX1(), getY1(), getX2(), getY2(), px, py);
}
/**
* Returns the square of the distance from a specified
* <code>Point2D</code> to this line.
* The distance measured is the distance between the specified
* point and the closest point on the infinitely-extended line
* defined by this <code>Line2D</code>. If the specified point
* intersects the line, this method returns 0.0.
* @param pt the specified <code>Point2D</code> being measured
* against this line
* @return a double value that is the square of the distance from a
* specified <code>Point2D</code> to the current
* line.
* @see #ptSegDistSq(Point2D)
* @since 1.2
*/
public double ptLineDistSq(Point2D pt) {
return ptLineDistSq(getX1(), getY1(), getX2(), getY2(),
pt.getX(), pt.getY());
}
/**
* Returns the distance from a point to this line.
* The distance measured is the distance between the specified
* point and the closest point on the infinitely-extended line
* defined by this <code>Line2D</code>. If the specified point
* intersects the line, this method returns 0.0.
*
* @param px the X coordinate of the specified point being
* measured against this line
* @param py the Y coordinate of the specified point being
* measured against this line
* @return a double value that is the distance from a specified point
* to the current line.
* @see #ptSegDist(double, double)
* @since 1.2
*/
public double ptLineDist(double px, double py) {
return ptLineDist(getX1(), getY1(), getX2(), getY2(), px, py);
}
/**
* Returns the distance from a <code>Point2D</code> to this line.
* The distance measured is the distance between the specified
* point and the closest point on the infinitely-extended line
* defined by this <code>Line2D</code>. If the specified point
* intersects the line, this method returns 0.0.
* @param pt the specified <code>Point2D</code> being measured
* @return a double value that is the distance from a specified
* <code>Point2D</code> to the current line.
* @see #ptSegDist(Point2D)
* @since 1.2
*/
public double ptLineDist(Point2D pt) {
return ptLineDist(getX1(), getY1(), getX2(), getY2(),
pt.getX(), pt.getY());
}
/**
* Tests if a specified coordinate is inside the boundary of this
* <code>Line2D</code>. This method is required to implement the
* {@link Shape} interface, but in the case of <code>Line2D</code>
* objects it always returns <code>false</code> since a line contains
* no area.
* @param x the X coordinate of the specified point to be tested
* @param y the Y coordinate of the specified point to be tested
* @return <code>false</code> because a <code>Line2D</code> contains
* no area.
* @since 1.2
*/
public boolean contains(double x, double y) {
return false;
}
/**
* Tests if a given <code>Point2D</code> is inside the boundary of
* this <code>Line2D</code>.
* This method is required to implement the {@link Shape} interface,
* but in the case of <code>Line2D</code> objects it always returns
* <code>false</code> since a line contains no area.
* @param p the specified <code>Point2D</code> to be tested
* @return <code>false</code> because a <code>Line2D</code> contains
* no area.
* @since 1.2
*/
public boolean contains(Point2D p) {
return false;
}
/**
* {@inheritDoc}
* @since 1.2
*/
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